Load devices with linearization technique employed therein

Abstract

A load device has tunable capacitive units including at least a first tunable capacitive unit and a second tunable capacitive unit with different inherent capacitive characteristics, respectively. Each of the first tunable capacitive unit and the second tunable capacitive unit has a first node and a second node, where the first nodes of the first tunable capacitive unit and the second tunable capacitive unit are coupled to a first voltage, the second node of the first tunable capacitive unit is coupled to a second voltage, and the second node of the second tunable capacitive unit is coupled to a third voltage.

1 . A load device, comprising:
 a plurality of tunable capacitive units, including at least a first tunable capacitive unit and a second tunable capacitive unit with different inherent capacitive characteristics, respectively, wherein each of the first tunable capacitive unit and the second tunable capacitive unit has a first node and a second node, the first nodes of the first tunable capacitive unit and the second tunable capacitive unit are coupled to a first voltage, the second node of the first tunable capacitive unit is coupled to a second voltage, and the second node of the second tunable capacitive unit is coupled to a third voltage.   
     
     
         2 . The load device of  claim 1 , wherein the first voltage is a control voltage configured for tuning capacitive values of the first tunable capacitive unit and the second tunable capacitive unit; and each of the second voltage and the third voltage is a specific reference voltage. 
     
     
         3 . The load device of  claim 2 , wherein the specific reference voltage is a supply voltage or a ground voltage. 
     
     
         4 . The load device of  claim 1 , wherein a voltage level of the second voltage is identical to a voltage level of the third voltage. 
     
     
         5 . The load device of  claim 1 , wherein a voltage level of the second voltage is different from a voltage level of the third voltage. 
     
     
         6 . The load device of  claim 1 , wherein the first voltage is a specific reference voltage, and the second voltage and the third voltage are control voltages configured for tuning capacitive values of the first tunable capacitive unit and the second tunable capacitive unit, respectively. 
     
     
         7 . The load device of  claim 6 , wherein the specific reference voltage is a supply voltage or a ground voltage. 
     
     
         8 . The load device of  claim 1 , wherein the first tunable capacitive unit and the second tunable capacitive unit are semiconductor devices with different semiconductor structures. 
     
     
         9 . The load device of  claim 8 , wherein the first tunable capacitive unit is one of a bipolar junction transistor (BJT), a heterojunction bipolar transistor (HBT), a high electron mobility transistor (HEMT), a field-effect transistor (FET), a varactor, and a diode, and the second tunable capacitive unit is another of the BJT, the HBT, the HEMT, the FET, the varactor, and the diode. 
     
     
         10 . The load device of  claim 1 , wherein the first tunable capacitive unit and the second tunable capacitive unit are semiconductor devices with different threshold voltages. 
     
     
         11 . The load device of  claim 10 , wherein a threshold voltage of the first tunable capacitive unit is one of a regular threshold voltage, a zero threshold voltage, a high threshold voltage, and a low threshold voltage, and a threshold voltage of the second tunable capacitive unit is another of the regular threshold voltage, the zero threshold voltage, the high threshold voltage, and the low threshold voltage. 
     
     
         12 . The load device of  claim 1 , being employed in a voltage-controlled oscillator (VCO). 
     
     
         13 . The load device of  claim 1 , being employed in a phase shifter. 
     
     
         14 . A load device, comprising:
 a plurality of tunable capacitive units, including at least a first tunable capacitive unit and a second tunable capacitive unit with substantially the same inherent capacitive characteristic, wherein each of the first tunable capacitive unit and the second tunable capacitive unit has a first node and a second node, the first nodes of the first tunable capacitive unit and the second tunable capacitive unit are coupled to a control voltage configured for tuning capacitive values of the first tunable capacitive unit and the second tunable capacitive unit, the second node of the first tunable capacitive unit is directly connected to a supply voltage, and the second node of the second tunable capacitive unit is directly connected to a ground voltage.   
     
     
         15 . The load device of  claim 14 , being employed in a voltage-controlled oscillator (VCO). 
     
     
         16 . The load device of  claim 14 , being employed in a phase shifter.